Power hoist mechanism



l Aug. 10 1926.

J. FARRELL POWER HoIsT M EcHANIsM Filed Feb. 12, ,1924

4 sheets-sheet 1 INVENTox Aug. 1o 1926. 1,595,508

J; FARRELL I POWER HOIST MECHANI SM Filed Feb. 12, 1924 4 `sheetsheet sVNO '4f 5' is BY y E x yedATToRNEYs.

Aug. l0 1926.

' 1,595,508 J. FARRELL l POWER HOI'ST MECHANISM Filed Feb. 12, I1924 4sheets-sheet 4 INVENTOR.

wz@ Jfzzfmll,

. BY y 2 @ATTORNEYS Patented Aug. 10, 1926. i

UNITED STATES PTENT QFEICE.

JOHN FARRELL, OF NEWTON, NEW JERSEY.

POWER.' HGXST MECHANISM.

Application led February 12, 1924. Serial No. 692,290.

This invention relates, generally, to yiniis a fragmentary detailhorizontal section proveinents in powerfhoists; and the inven- Yon anenlarged scale, illustrating the novel tion has reference,A moreparticularly to means for adjusting the friction blocks of hoistingmechanism having` a plurality of the drinn clutch mechanism; Figure 6 isa 60 5 drums operated byfriction clutch transmisface view of one of thefriction blocks as sion mechanism, and provided with a novel supportedand carried by said adjusting single lever control mechanism by means ofmeans; and Figure T is a perspective view which the operation of thedrums may be seof the friction block adjusting means alone. lectivelycontrolled at will. Figur-e 8 is a plan view of a somewhat 65 l0 Theinvention has for its principal object modified construction of powerhoist mechato provide a very simple and yet etiicient nlsm whichembodies, however, the primi single lever control mechanism for hoistingplee Of the present invention; and Figure 9 machines possessing aplurality of drums, iS 2L fragmentary vertical cross-section, takenwhereby the drums may be selectively put Online 9-9 in said Figure 8. 70into operation, said single lever control Figure l0 is a view similar tothat shown mechanism being of such novel construction in Figure 3, butillustrating another modithat it may, if desired, be actuatedfioin afied COnStruCtOn of the power. hoist control distance by means of asingle rope attached mechanism made according to and embody to the hondlover. ing the principles of this invention; and 75 The invention alsohas for another object Figure ll iS a fragmentary vertical cross toprovide various detail improvements in SeCtIOn, taken 0n line ll-ll insaid power hoists of the kind described, such as Figure l0. an improvedconstruction of brake mecha- Slmllal" CharaCters of reference -areeninisin for the main drum, and an improved PlOYQCl lllall Of thehereinabove described 80 means for adjusting the friction blocks ofWSWS, t0 111611021@ COlreSpOIlCllDg parte. tho drum olutoh meohanism,Referring now to said drawings, the refthor objects of the invention,not at this erence character l() indicates one side frame time moreparticularly enumerated, will be and, 11 HlCllCilfeS, the Other sideframe upon Clearly understood from the following dewhich the hoistingmechanism is mounted. 85 tailed desogpton of the Sama hach side frame isprovided intermediate lilith the various objects of this inventiontSfend's with a belnfsr member 12- JOUY* Yin view, the same consists,primarily, in the Billed in Said bearing members so as' to novelconstruction of power hoist mechanism @Xtell CHIHSYGFSGX between Saidbearing hereinafter set forth; and, the invention conmemlelS l2 lS'adrive Shaft 13, having af-` 90 sists, furt iermore, in the novelarraneje- X'Gd t0 011 @11d 21 belt Pulley 14, Or Other ments andcombinations of the various de- Sultbl@ 19ans fol" applying POWGTtht/fet()- vices and parts, as well as in the `details of FXd PDB Saddrive Shaft 13 Mila-Cent t0 the construction of the same, all of whichthe lunar Side ,of the 51de frame lo 1S a will be hereinafter more fullydescribed, and SPM" gem. D a 95 then finally embodied in the claimsappended ElCh Std@ fram@ 1S @ber PlOVded, 11C-lto this Specificationjacent to its one end, with a bearing member The i vention is clearlyillustrated in the 16- EXte/nflmg tlSVeSely lOQlWGGII 'Seidaooomponyingdrowingo, ilo Wh@h bearing members 16, and suitably aiXedFigure l is a plan view of the novel con* tht/Wto, 1S 2 DQR-Tollltabl@Shaft 17- SUP" 100 struction of power hoist mechanism made Ported UPOHSlfl Shaft 17, RC1-.Meent t0 the ooooyding to mdv embodying theprinciples inner side of said side frame '10, and so asl of thismvonton; Figura@ 2 'j-S a Sido olovoto freely rotate thereon, is a gearwheel i8, tion of the somo; Figure 3 is a ffagmontoyy which operativelymeshes with and is driven longitudinal vertical section, taken on lineby said spur gear l5 of the drive shaft 13. 105

8-3 in said Figure l and drawn on an en Mounted upon the inwardly facingeide of larged scale, said view showing the novel said gear wheel-18 area plurality of fricsingle lever control mechanism in neutralv ion blocks19, the outer ends of which are position by full lines, and in theselective shaped to provide inclined friction faces 20.

operative positions by dotted lines; Figure Each friction block '19 is'adjustably sup- 110 a is a fragmentary vertical cross section, portedby a novel means, the saine compristaken on line l-/l in said Figure 3;Figure ing a cylindrical main body 2l which eX- a tends through and isrotatably mounted in the body of the gear wheel 18. Said cylindricalbody' 21 is provided at its outer end with an enlarged head 22, whichengages the outer face of the gear wheel body to pre vent inwardlongitudinal displacement of said cylindrical body 21. Projecting fromthe inner end of said cylindrical body 21 is an eccentrically od-setcarrier stud 23, which extends tl rough the friction block 19, and whichsupports the same. yhe cylindrical body 21 and the carrier stud 23 aretogether provided with a longitudinally eX- tending through opening 24.Extending through said opening 24 is a bolt 25 having at its inner end ahead 26, which, with a washer 27, bears against the friction block 19.The outer end of said bolt 25 is threaded to receive a nut 28. l.When itis desired to adjust the friction block, to compensate for wear or forany other reason, the nut 28 is loosened, and the cylindrical body 21 isturned to rotate the eccentrieally off-set carrier stud 23, which byreason of its eccentricity relative to the axis of the oylindrical body21, will cause the friction block to be shifted outwardly or inwardly,as the occasion may require. When the desired adjustment of the frictionblock has thus been made, the same may be looked or lixed in the desiredadjusted position by again tightening up the nut 28, whereby the head 2Gof the bolt 25 draws the friction block 19 into strong frictionallybound or clamped relation to the inner surface of the gear wheel 18, allof which will be readily understood from an inspection of Figures 5, Gand 7 of the-drawings.

The reference character 29 indicates a main hoisting drum which isloosely mounted upon the shaft 17, and which is also capable of a slightlongitudinal shifting movement on said shaft 17. The flange of said drum29, which is adjacent to said gearwheel 18, is provided with an annularclutch member 30, the inner side of which is inclined to provide afriction face 31 adapted to conform to and receive the engagement faces2O 0f the friction blocks 19, when said parts are operatively engagedtogether by shifting the drum 29 longitudinally toward the gear wheel18. A compression spring 32 is disposed around the shaft 17 intermodiatethe hubs of said gear wheel 18 and said drum 29 to normally hold thedrum clutch member disengaged from the friction blocks 19 of the gearwheel 18.

Each side frame is further provided, adjacent to its opposite end, witha bearing member 33. Extending transversely between said bearing members33, and suitably afliXed thereto, is a non-rotatable shaft 34. Supportedupon said shaft 34, adjacent to the inner side of said side frame 10,and so as to freely rotate thereon, is a gear' wheel 35, whichoperatively meshes with and is driven by said spur gear 15 of the driveshaft 13. Said gear wheel 35 is provided on its inwardly facing sidewith an annular flange which provides a female clutch mem ber 3G. Thereference character 37 indicates an auxiliary or return hoisting drumwhich is loosely mounted upon the shaft 34, and which is also capable ofa slight longitudinal shifting movement ou said shaft 34. The flange ofsaid drum 37, which is adjacent to the gear wheel 35, is provided with amale clutch ineniber 38 adapted to frictionally engage the female clutchmember 36 of the said gear wheel 35, when said drum 37 is shiftedlongitudinally toward said gear wheel 35. Means such as aV spring (notshown) disposed and arranged in a coopera` tive relation between thegear wheel 35 and orum 37, similar to the above described relation ofthe spring- 32 to and between the main drum 29 and the gear wheel 18,may be employed to normally hold the drum clutch member 38 disengagedyfrom the female c-lutchmember 36 of the gear wheel 35.

The novel single lever control means for selectively shifting either oneor the other of said drums into clutched relation to the powertransmission mechanism, comprises the following elements Connected withthe bearing member 16 of the side frame 11 is an inwardly projeotingboss or hub 39, the free end of which is shaped to provide al stationaryend-thrust cam 40. Fulcrumed on the shaftlr intermediate Y- the adjacenthub-portion 41 of said hoisting drum 29 and said sleeve or hub 39, is abell-crank device, consisting of a fulcrum sleeve 42 journaled on saidshaft 17; said fulcrum sleeve having an upwardly extending crank-arm 43,and. a laterally projecting crank-arm 44 which projects toward the 1.)7' f. hoisting dium of. The outer end of said fulcrum sleeve is shapedto provide a m,oV- able end-thrust cam 45, which abuts and cooperateswith said stationary end-thrust cam 40.

Associated with said bell-crank device is a yieldable stop means, whichcooperates with a fixed stop nosing 46 with which the upper surface ofsaid boss or hub 39 is provided, and which is adapted to normally engagethe latter to determine the normal initial or neutral position of saidbell-crank device :ind of the cam means with which the latter isprovided. Said yieldable stop means comprises a housing member 47provided with laterally and oppositely projecting wings or lugs 48through which extend bolts 49, or other suitable fastening means,whereby said housing` member 47 may be secured to the outer side of saidbell-crank device. Said housing member 47 is so disposed, whenoperatively connected with said bell-crank device, as to projectlongitudinally forward il D so as to overhang said stationary boss orhub 39. Said housing' member l? is provided. at its lower or under sidewith a soclret in which is arranged a stop-roller 51. Eatending upwardlythrough said housing` member et? above said socket 50 is a vertical borein which is arranged a. compression spring 53, which thrusts downwardlyupon said stoproller 5l to yieldahly engage the latter with the uppersurl'ace ot boss or hub The tension or" said spring 5S is regulated byan adjusting screw 5d which is threaded into the bore 52 Vtrom the upperend ot said housing member e7.

Snitably secured to the upwardly e-:tending crank-arm ot the bell-crankdevice is a control lever It the mechanism to be controlled by anoperator stationed at the hoist, said control lever may be so ailiiiedto said bell-crank device as to project vertin cally upward therefrom;it, however, he mechanism is to be controlled from a .istance throughthe intermediation oi a pull rope, as 56, attached to the control lever,the -it is preferable that the latter be so afiired to the crank-arm d3as to incline from the vertical, or, in other words, to extend obliquelyupward in a direction toward the auxiliary hoisting drum. ln the latterarrangement or disposition ot said control lever, the same is provided,adjacent to its tree end with a weight men-iber 5T, so that when thepull rope 56 is relaxed, the torce of gravity acting on the weight willswing the iev-xr in a direction opposite to that in whch it is moved bya pull upon said rope.

Normally the bell-crank device and its end thrust cani means is disposedin neutral position wherein the stop-roller 5l is held stopped againstthe stop-nosing 4G, and as an aid .to holding and returning the parts tosuch neutral position, the lulcrum sleeve d ot said bell-crank device isprovided on its underside with perrorate ear or lug 58 to which isattached one end ot a pull spring 59, the opposite end ot which isanchored to the side trame il, by connection thereof with an anchor post60 iith which said side trame is provided.

That par of the single lever control mechanism which cooperates with theauxiliary drum 3T, comprises a wedge-plate Gl, which ispreferably'biiurcated so as to straddle the shalt Bfl on which said drum37 is mounted. -aid wedge-plate Gl is adapted to bear et the hub-portionS ol saio auxiliary ruin 37, and, it desired, one or more washl may beinterposed between said hubo2 and said weils-opiate Tdined on sa hattSli is a collar or thrust-bloei; @el p ned on its inner Ytace withthrustlugs against which the wedge-plate is backed. Sail wedge-plate nlis interconnectec with said bell-crank device by linlz bar 66 which ispivotally connected by one end to said wedge-block, and by its other endto said laterally projecting crank-arm 4:4 of said bell-crank device,preferably by means of one of the fastening bolts 49.

'ihe hoisting mechanism, constructed as abovedescribed, is furtherprovided, in connection with the main drum 29, with a novel constructionand arrangement o'f brake mechanism. This bralre *'iec ianisin coni- ,rrles an annular bralre drum Ytlange 67, which projects iroin one end ofthe drum Q9. Y ly 'from the side iframe il is a ilulcrum stud (38 uponwhich is pivotally mounted a bellcrank lever G8, to one arm 69 oit whichis suitab v connected one end oiv a 1uralte-band T0, which encirclesbrake drum flange 6?, and the other arm 'Zi ot which is provided,intermediate its ends with an anchor arm "ifi, to which the opp site endof said brake-band 270 connected'. i helical spring 73 encircles the hubportion ol' said bellcrank lever (S8, and one branch thereof is anchoredon an anchor pin 7 which projects inwardl trom said side trame il, andthe other branch oit which is connected with an attachment stud Z5 withwhich the arni G9 ot the bei -lr lever is provided. The tension ot pring73 tends to normally return said bell-cranh lever to a normal initialbrake-band releasing position. Said bellcranl; lever is oper ted, to inturn actuate said bralrediand 70, by means ot an operating lever 7J,which is Afulcruined on said side 'trame lle, and pivotallyinterconnected, at a point intermediate its free end and its fulcrum,with the end ot said arm 7l of said bellcranlr lever by means of acoupling` pin "17. rShe iree end ot said operating lever 75 terminatesin a fiat treadle portion 78.

rllhe side trame ll is provided with a plurality or ratchet teeth Z9with which said operating lever 76 may be selectively engaged, when thesame depressed to operate said bell-crank lever and thus in turn actuatesaid brake-band TO, thus holding the brake-band in braking relation tothe brake druni iiange 67, when it is desired so to do. lt will beunderstood, trom an inspection of JFigures l and Q more particularly,that` the depression or downward swinging movement ot the operatinglever T6 will swing downwardly the bell-c 1ank lever arm 7l andoutwardly the bell-crank lever arm G9, whereby the brake-band iscontracted about the brake drum liange t3?. 'lt will also be understoodthat the interrelation of the bell-crank lever G8 and operating lever 76is suchV that the leverage is compounded, so that comparatively littletorce applied to the latter l be increased or compounded to 'produce avery powerful contraction ot trie brake-band 70 relative to the brakedrum `flange G7.

The novel construction ot hoisting mechllO anism above described isparticularly adapted for hay handling, for hoisting ice into ice houses,for coal handling and many other hoistino' operations. In many of suchhoisting operations it .is desirable foiI the operator to be enabled tocontrol the operation of the hoisting drums from a distance, as, forexample, when handling' hay, to be able to control the operation of thehoisting` drums from the top of a load of hay, whereby the operator mayboth attend the handling of the hay-fork in loading the saine, as wellas the control of the hoisting drums. Ilo this end the novel singlelever control mechanism above described is readily and efficientlyadapted. In hay handling the main drum 29 is utilized to lift the loadand to operate an overhead carriage for running the loaded hay-fork intothe barn and hay-mow. Assume that the hay-fork has been lowered to thetop of a loaded wagon and charged or loaded with hay to be hoisted upand run into the barn and mow. l/Vhen ready to hoist, the operator pullsupon the rope or line o which swings the control lever to the left, thusrotating the bell-crank device so that the end thrust cam Li5 of itsfulcrum sleeve 119 is operatively rotated against the stationary endthrust cam 40. Such actuation of the cam devices causes the sleeve 42 toshift inwardly upon the shaft 17, and iii turn shifts the main drum Q9to cause the clutch mechanism intermediate the same and the rotatinggear wheel 1S to engage, so that power is `ransmitted to the drum 29 andthe loaded hayfork is thereupon lifted up to the entrance of the barnand mow (the described operation of the hoist control mechanism beingillustrated by the dotted representation of the same shown in Figure 3and indicated by the reference character rhe loaded hayfork having thusbeen hoisted to the overhead conveyer or carriage and then to thedesired position in the mow, the Voperator relaxes the rope or line 5G,so that the .ii'eight 57 of the lever 55, aided by the spring 59,returns the control mechanism to normal initial position, with the stoproller 5l stopped against the stop-nosing e6, in which position theclutch mechanism of the drum 29 is released and the drum is stopped.Since, how-ever, it is desirable to immediately operate the drum 37 toreturn the carriage and fork outward over the load, so the fork maydescend, the operator when relaxing the rope or line 56, does so with aquick movement, so that the control lever 55 and bell-crank device willby its momentum cause the yieldable stop-roller 5l to ride over thestop-nosing 46, thus allowing the control lever and bell-crank device tomake a complete swing to the right. Such opera tion causes the arm Le ofthe bell-crank device to push onward the link bar 66, and toconsequently move outward the wedge-plate 6l, with the result that thedrum 37 is shifted to throw its clutch mechanism into operation, wherebyrotative power is transmitted to the drum 37 through the gear whee 35,and thereupon the carriage returns along' its track under the pull ofthe rope wound up on the drum 37. When the drum 37 is thus operating themain drum 29 is released so that the hay-fork hoisU rope attachedthereto will unreel as the carriage returns to original position overthe load and the hay-fork descends (this described operation of thehoist control mechanism is illustrated by the dotted representation ofthe same shown in Figure 3 and indicated by the reference character y).

I? rom the above description the convenience and efi'iciency of thecontrol mechanism will be readily understood by those skilled in the artto which this invention relates.

Referring now to Figures S and 9 of the drawings, I have illustratedtherein a typ-e of double drum hoisting machine, in which the separatetix-ed shaft 34 has been eliminated, and the auxiliary hoisting drum 37is shown loosely mounted with its clutch mechanism upon the drive shaft13, the latter having a larger gear wheel S0 fixed thereon, which meshesdirectly with the wheel I8 operating the main drum.

The above described single lever controlv mechanism for the hoistingdrums of this simplified arrangement of mechanism, is, in allsubstantial respects, constructed in the same manner and functions inthe same manner as already above described, and as will be evidenced bythe use of the same reference letters to identify the correspondingparts.. Thereis one slight diiference, however, to which attention maybe called. This diiference consists in mounting the thrust block 64loosely upon the shaft 13, and providing the same with keeper lugs 8lwhich straddle the wedge-plate 6l, whereby the thrust block 64e is heldagainst rotation with the shaft 13. A collar 82 fixed by a set screw 83may be arranged on the shaft A3 in back of the thrust block 54, wherebythe latter may be set up or adjusted relative to the wedge-plate and thedrum 37 actuated thereby.

Referring to Figures l0 and ll of the drawings, I have illustratedtherein another modified arrangement of the single lever controlmechanism for selectively operating the hoist drums. In this modifiedarrangement, instead of mounting the yieldable stop means in connectionwith the bell-crank device and associated parts as above de` scribed, Ieliminate said yi-eldable stopmeans from such connection, and provide inassociation with the wedge-plate 6l a yieldable stop means of 4somewhatsimilar character. In this modified form and location,

said yieldable vstop means comprises a stopnosing 841- which is suitablylocat-ed on the upper edge of said wedge-plate 61. Mounted on the shaft34 is a thrust-block S5 provided on its inner e with thrust lugs S6,against which the wedge-plate 61 bears. Connected with the upper sideof said thrust-block 85, and .so disposed as to overhang saidwedge-plate 61 is a housing member 87. Said housing member 87 isprovided at its lower or under side with a socket 88 in which isarranged a stop-roller 89. Extending lupwardly through said housingmember .87 above said socket 88 is a vertical bore 90 in which isarranged a compression Ispring 91, which thrusts downwardly upon .saidstop-roller .89 to yieldably engage the latter with the upper edge ofsaid wedge-plate 61. The tension of the spring 91 is regulated by anadjusting screw 92 which is threaded into the bore 90 from the upper endof said housing member Vh-en the parts of the single lever controlmechanism are in normal initial or neutraly position (as shown in Figure10), the stopnosing 84 is held stopped against the stoproller 89. henoperating the mechanism devices ofthe drum 37, the control lever 55 willbe allowed to drop with a quick movement, so that wedgep'late 61 will besuddenly forced forward whereby its stop-nosing 841-. will forceupwardly the spring pressed stop-roller' 89, thus allowing thewedge-plate 61 to move forward or outward, wi-th the result that th-edrum 37 is shifted to throw its clutch mechanism into operation.

I am aware that some changes may bel made in the mechanical design andin lthe arrangements Vand combinations of the several devices and partsVof the novel hoisting mechanism abov-e described, as well as in th-edetails of 'the construction thereof,

without departing from the scopeof this -i-nvention .as set forth in theforegoing specification, and v-as defined in the appended claims. Hence,Ido not limit my invention to the exact arrangements and combinations ofthe devices and parts Ias described in said specification, nor do Ilimit myself to the exact details of the construction of saidv parts asillustrated in the accompanying drawings.

1. In a power hoist, lthe combination with a plurality of drums, a shafton which each drum rotates, a. power transmission means, a clutch meansintermediate each drum and said power transmission mea-ns, a singlelever control mechanism fulcrumed on one of said drum supporting shaftsfor intermittently and alternately shifting said drums into clutchedrelation to said power transmission means, a housing member affixed tosaid single lever control mechanism adjacent to its fulcrum, an upwardlyyielding springpressed roller mounted in said housing member, astationary stop-nosing engageableby said roller to determine the neutraldrum releasing position of said control mechanism.

2. In a pow-r hoist, a supporting frame, a plurality of drums a shaftmounted on said supporting frame for supporting each drum, a powertransmission means, a clutch means intermediate each drum and said powertransmission means, a single lever control mechanism comprisingbell-crank device having a fulcrum sleeve pivoted on the shaft of one ofsaid drums, a single control lever aflixed to one arm of said bell-crankdevice. said supporting frame having a stationaryY end thrust cam, saidfulcrum sleeve having a vrotatable end thrust cam to cooperate with saidstationary end thrust cam, a stationary thrust block on the shaft of theother of drums, a wedge-block slidable between said thrust bloclr andthe hub of said latter drum, a 'link-bar interconnecting saidwedge-block with the other arm of said bell-crank device, and ayieldable detent means for determining the neutral drum releasingposition of said single lever control mechanism.

3. In a power hoist, a supporting frame, a plurality of drums, a shaftmounted on said supporting frame for supporting each drum, a powertransmission means, a clutch means intermediate each drum and said powertransmission means, a bell-.crank device having a fulcrum sleeve pivotedon the shaft of one of said drums, a single control lever aiiiz-:ed toone arm of said bell-crank device, said supporting frame havingastationary end .thrust cam, said fulcrum slee-ve having a rotatableend'thrust cam to cooperate with said stationary end thrust cam, astationary thrust block on the shaft of the other o-fsaid drums, awedge-block slidable between said vthrust bloclrand the hub of saidlatter drum, a link-bar interconnecting said wedge-block with theotherarm of said bellcrank` device, a yieldable stop means carried bysaid bell-crank device, and a stationary stop-nosing connected with saidsupporting' frame and lengageable by said y-ieldable stop means todetermine the neutral drum releasing position of said bell-crank device.and associated parts.

el. "In a power hoist, a supporting frame, a plurality of drums, a shaftmounted on said supporting fra-me for supporting each drum, a 'powertransmission means, la clutch means intermediate each drum and saidpower transmission means, a bell-crank device having a fulcrum sleevepivoted on the shaft of one of said drums, a single control lever amazedto one arm ofv said bell-crank device, said supporting frame having astationary end thrust cam, said fulcrum sleeve having` a rotatable endthrust cam to cooperate with said stationary end thrust cam, a

stationary thrust block on the shaft of the other of said drums, awedge-block slidable between said thrust block and the hub of saidlatter drum, a link-bar interconnecting said wedge-block with the otherarm of said bell-crank device, a housing member aliixed to saidbell-crank device above the fulcrinn sleeve thereof, an upwardlyyielding springpressed roller mounted in said housing member, astationary stop--nosing connected with said sup sorting frame andyieldably engageable by said roller to determine the neutral drumreleasing position of said bell-crank device and associated parts.

5. ln a power hoist, the combination with a plurality of drums of powertransmission means, clutch means intermediate said drums and saidtransmission means, a single lever control mechanism for .intermittentlyand alternately shiftin said drums into clutched relation to said powertransmission means, a pull rope for controlling operative oscillation ofsaid single lever control mechanism in one direction, a weight on saidsingle lever control mechanism for producing operative oscillationthereof in the opposite direction, and spring means for holding saidsingle lever control mechanism in neutral position.

6. In a power hoist, the combination with a plurality of, drums of powertransmission means, clutch means intermediate said drums and saidtransmission means, a Single lever control mechanism for intermittentlyand alternately shifting said drums into clutched relation to said powertransmission means, a pull rope for controlling operative oscillation ofsaid single lever control mechanism in one direction, a weight on saidsingle lever control mechanism for producing operative oscillationthereof in the opposite direction7 a yieldable stop means carried bysaid single lever control mechanism, and a stationary stop-nosingengageable by said yieldable stop means to determine the neutral drumreleasing position of said control mechanism.

7. In a power hoist, a supporting` frame, a plurality of drums, shaftsmounted on said supporting frame for respectively supporting each drum,a power transmission means, a clutch means intermediate each drum andsaid power transmission means, a bell-crank device having a fulcrumsleeve pivoted on the shaft of one of said drums, a single control leverafxed to one arm of said bellcrank device to extend obliquely therefrom,said supporting frame having a stationary end thrust ca n, said fulcrumsleeve having a rotatable end thrust cam to cooperate with saidstationary cam, a stationary thrust block on the shaft of the other ofsaid drums, a wedge-block slidable between said thrust block and the hubof said latter drum a link bar interconnecting said wedge-block with theother arm of said bell-crank device, a pull rope for controlling'operative oscillation of said control lever in one direction, a weighton said cont-rol lever to produce oscillation thereof in the Oppositedirection when said pull rope is relaxed, and a yieldable detent meansfor determining the neutral drum releasing position of said controllever.

ln a power hoist, a supporting frame, a plurality of drums, shaftsmounted on said supporting` frame for respectively supporting each drum,a power transmission means, a clutch means intermediate each drum andsaid power transmission means, a bell-crank device having a fulcrumsleeve pivoted on the shaft of one of said drums, a single control levcraffixed to one arm of said bellcrank device to extend obliquelytherefrom, said supportingframe having a stationary end thrust cam, saidfulcrum sleeve having a rotatable end thrust cam to cooperate with saidstationary cani, a stationary thrust )loch on the shaft of the other ofsaid drums, a wedge-block slidable between said thrust block and the hubof said latter drum, a link bar interconnecting said wedge-block withthe other arm of said bell-crank device, a pull rope for controllingoperative oscillation of said control lever in one direction, a weighton said control leverv to produce oscillation thereof in the oppositedirection when said pull rope is relaxed, a housing member aiiired tosaid bell-crank device above the fulcrum sleeve thereof, an upwardlyyielding spring-pressed roller mounted in said housing member, astationary stop-nosing connected with said supporting frame andyieldably engageable by said roller to support said weighted cont-rollever so as to determine the neutral drum releasing` position of saidbell-crank device and associated parts. v

ln testimony, that I claim the invention set forth above I have hereuntoset my 'hand this 7th day of February, 1924.

JOHN FARRELL.

Bil

